Keep tcc locked in 4th

[gman4dx266]

Yeah there is nothing similar between the vette's A6 and a plain vanilla 4spd at all. I really cant do anything with that file except open it, nod and smile knowing that it works for you.

The tow rating thing is stupid. If ANYTHING, GM should have made this 4th unlock crap only active in the Performace Mode, whenever that is clicked on.

Either way, when it all boils down to the nuts and bolts (or ones and zeros, rather) If (and it probably is) it is PCM related, it can be changed. Just a matter of getting our peeps to let us have access to it.

[SS_bnoon_SS]

The 65E in my SS unlocks on decel too. I tried turing the duty cycle up to 100, set all lock speeds the same down to 0%, and nothing has worked. When I used to tune my old '86 Trans Am, GMECMEdit had a parameter called "TCC Coast Delay" or something like that and I could tell the ECU how long to wait on coast before it would release... It was worth 4 MPG on that car to force it to hold lockup. Can't believe the newer PCM wouldn't have something like that in there, very frustrating. I almost want to put a manual switch/relay to lock it when I want.

[gman4dx266]

When I used to tune my old '86 Trans Am, GMECMEdit had a parameter called "TCC Coast Delay" or something like that and I could tell the ECU how long to wait on coast before it would release.

Can't believe the newer PCM wouldn't have something like that in there, very frustrating. I almost want to put a manual switch/relay to lock it when I want.

Betcha it's still in there

[SS_bnoon_SS]

Betcha it's still in there

Just got to get someone to write it into the def file so we can modify it. Either that, or give me open code access to hack the mask/bin myself. LOL!

[gman4dx266]

Either that, or give me open code access to hack the mask/bin myself. LOL!

I HIGHLY dobut [meaning I'm telling you it wont happen] that they will give you the source code.

...But assuming you did come across such, how bout hookin a brother up with some lean cruise as well *cough cough*

But back to topic...

Since you [SS] said your old TA used to do it (this unlocking business) then that rules out it being a 'trailering feature' like someone said in this thread. Atleast, I dont know many people personally who tow with an Fbody, but hey I could be wrong

[SS_bnoon_SS]

I towed my single person watercraft with the TA, and a two place snowmobile trailer... but I'm just weird like that.

If I ever did get open source code, I'd write in more MAF resolution, lock the damn converter when I want it locked, and write in the AC turn on pressures into the Fans area (to go high fan speed at lower AC pressure). Outside of that... I just keep making posts in the "features" section hoping to convince HPT to write them in for us.

[gman4dx266]

I just keep making posts in the "features" section hoping to convince HPT to write them in for us.

Why didn't I do that for my problem!!!! I'm such a loser i swear. I didn't even THINK of posting in there! goshdang.

[Blades]

The tow issue/hypothesis would be solved if someone with an A4 SSR chimed in.. Truck platform (GMT360), car accessories (6spd available), I don't think it has that much of a 'tow rating'. Again, its just a guess. Seems odd that the A4 GTOs do not have this problem.

[gman4dx266]

The tow issue/hypothesis would be solved if someone with an A4 SSR chimed in.. Truck platform (GMT360), car accessories (6spd available), I don't think it has that much of a 'tow rating'. Again, its just a guess. Seems odd that the A4 GTOs do not have this problem.

Good luck, not many of those around, let alone A4's.

If that does happen to work though, Im guessing some patch could be derived from the 'good' file to fix the 'bad files'.

Hmm, Id be curious to see a 5.3L Monte Carlo...er...not see, but hear about what it does and how it acts in relationship to this thread.

[always last]

On the chevy listed below I lock in at 73mph and I remain locked untill I get under 35mph even with 0tps. As long as I stay above 35 I stay locked in normal mode. I'm going to move the 35 to 50 - 55. 35 is a little low. I hate that lock unlock shit. If you haven't figured it out I'll log a run and post my settings.

[gman4dx266]

No sir, no one has figured anything out on it at all.

What operating system are you running? is it 12212156?

If possible can you post up your tune? Id atleast like to get mine to behave like yours to where it will unlock at 35-ish. It's better than it going on,off,on,off, etc on the interstate. It raises my AT temps a good bit, since i need to have PWM enabled in my tcc for the 'ride quality' [read: non-jerky]. Although my values are high (68 is the lowest in the min table)

[always last]

My os is 127012,

The motor is a 6.0 4l80 out of a 2000 2500 HD from the bone yard. I'm also running the vcm that came with the bone yard motor and trany. I posted a run I made. You'll see that the trany stays locked even at 0 tps. It unlocked once when I hit the brake. The trany is set to lock at 70, but locks a little higher.

Look at TCC Apply/Release Speed vs TPS vs Gear - Normal
I set 4th to 70 on the first three. It locks in around 73 to 75 at that TPS, but if you pass the 12.50 getting up to speed entering the highway it stays unlocked until you drop down to 12.50 over 73. Thats why I left the upper numbers at 255. I can run up to 85 with out locking and then let the throttle off to 12.50 and lock up, step on it and it stays locked.

The posted was set to lock at 70 and unlock at 35. I tried the 4th release at 50 and it started to lock unlock on me, so I'm back to 35 for now.

I also set the shift lock to Disable.

This is not a tune I run all the time. It's one I test on. and I am not a trany pro. But I read this post and figured I try to help and this worked.

[gman4dx266]

Thank you for posting that, Always Last! I'll try that. If that doesn't work, then it further reinforces my hunch that its the VCM OS, as you're running 1271012. [By the way, the scanner & editor report your truck as a 2001 for whatever reason, even though you say it's a 2000]

Hmm, what doesn't make sense though, I see that you have, for 4th release, 35 across the board. Whats retarded is that I currently have mine @ 0. I've also tried 256mph. You'd think that since they're both extreme ONE of the two would work, so that right there makes me go 'wtf' lol

...But like i said, ill try it. Doesnt hurt.

I'd hate to do it, but perhaps if the HPT people can provide a fix or allow me to do a write entire of a 1271012 to my VCM or something, my only other option is do go to the boneyard, and pull a VCM from a 2000 2500HD, and relicense the damn truck a 3rd time. Id like to stay away from that, since its quite expensive (VCM cost & credit cost).

[95aqua]

Was there ever a resolution to this?

I have a 2001 2500 that does the same thing and its really annoying. I just started working with this tuning software and this is one of the first things I've tried to eliminate with no success.

[gman4dx266]

No sir, still nothing. That behavior really pisses me off, and raises my temps up.

I have some extra info, not much but some.

Ok the converter unlocks with anything below FIVE percent throttle. (4 and under will be unlocked) That said, If im cruising along at say, 40mph, and I let off a bit to bring it down to 5% tps...keep it there for a second or two just to get it all stabilized, and then lower it to 4% you'll see the TCC mode say 'release' for a split second and then 'off'. That being said, a release is being commanded by the VCM, which means it should be in the programming somewhere.

EDIT: I have emailed Support@HPT again.
EDIT x2: I have bill@hpt helping me; looking at my logs & tune right now. Hope this can get figured out for all us truck guys! Keep your fingers crossed ladies and gents!

[Trever1T]

Everyone with 4L80es that I have talked to has this issue. My built 4L65e was unlocking when i released the throttle when i first started playing with all the tables. By adding values into the 0% TPS cells I was able to get the converter to remain locked even though my dbw throttle body never see's 0%tps...
From the guys I've talked to this does not work for the 80e's.

[gman4dx266]

Everyone with 4L80es that I have talked to has this issue. My built 4L65e was unlocking when i released the throttle when i first started playing with all the tables. By adding values into the 0% TPS cells I was able to get the converter to remain locked even though my dbw throttle body never see's 0%tps...
From the guys I've talked to this does not work for the 80e's.

Yeah man, believe me Ive tried that route already, and they had no effect on anything. I've got my fingers crossed in hopes Bill@HPT will help me out and get something out for us 80E guys. I can keep the clutch engaged 100% locked in 4th gear using the VCM controls, so it's physically possible for it to do it, I've gotten that far. It's just a shortcoming of the VCM somewhere, or a shortcoming of HPT for not finding it...perhaps both. So far besides my truck, An 07 Trailblazer LL8 (4l60) and an 02 Impala 3400 (4T60?) does this crap as well. But they arent tuned, so they may be able to have that corrected off the bat with a tune. Bill said his pontiac car does this as well, but doesnt have a table in there to correct it as of now, and told me that he would take my truck file and submit it along side his file and see if anything could be found to help out. So far that is all the news I have.

...Maybe while they're in there, they can figure out why i cant peel out at all. lol thats wishing though.

[Frost]

*cough*

[gman4dx266]

*cough*

Yeah for real! Theres gotta be some info by now!

[Frost]

really need to know if this is even possible...